Plug-type connectors for detachable mechanical connection and locking of electrical connections are known in numerous embodiments. The requirements of the securing properties of the plug-type connector are extremely high, particularly in safety-critical connections, such as the electrical connection between an igniter, for example of an airbag and/or a belt tensioning device, and an electrical control device of an occupant restraining system in motor vehicles. It should not, under any circumstances, be possible for a plug-connector of this type, once it has been connected for example during assembly of the motor vehicle, to be able to independently detach again, not even as a result of impacts, jolts, vibrations or similar mechanical effects.
To achieve a high holding force in plug-type connectors, these connectors comprise variously configured blocking or locking devices. High demands with respect to flexibility and rigidity are placed on these devices. On the one hand, it must be possible to produce the plug-in connection, in other words, it must be possible to introduce the connecting device, projecting from the connector housing, into the corresponding openings of the socket. If the connector is in the correct position, i.e. if the connecting device is inserted to a sufficient depth into the socket and, for example in the case of an electrical plug-type connector, an electrical contact is produced, a locking device should produce such a high holding force that detachment of the connector is no longer possible or is only possible by applying an appropriately high force or by mechanical unlocking.
Lockable plug-type connectors frequently comprise a flexible connecting device and a rigid locking device which are constructed separately from each other. In the case of such plug-type connectors the actual plug-in connection is produced in that the connecting device projecting on the connector housing is introduced into the socket, wherein the connecting device can, on the one hand, produce a directional guide and, on the other hand, can comprise a mechanical arresting and/or securing device. Only thereafter, for example as a result of activation of a blocking key, displacement of a slide or another type of mechanical movement, is locking of the plug-type connector implemented in that a more rigid securing element is introduced which either provides for secure retention of the connector in the socket on its own or the still relatively slight holding force of the plug-type connector, produced by a mechanical arresting and/or securing device on the connecting device, is assisted and the overall holding force thus increased.
An example of a plug-in connector of this type is described in DE 102 02 920 A1.
Plug-type connectors are also known which likewise have the requisite holding properties and in which no additional mechanical action on a plug-type connector portion is required after insertion into the socket. Mating is possible in such plug-type connectors in the presence of any flexible and less flexible components of the locking device. The secure, locked connection is produced by the action of insertion; no further intervention is necessary. This reduces the assembly time and can also prevent application of mechanical locking from being forgotten.
However, a drawback of connectors of this type is that, on insertion of the connector into the socket, an insertion force has to be applied which is directed counter to the holding force in the closed connector and which corresponds in size to the holding force. A high insertion force inevitably results with a high holding force in systems of this type.